An operating principle of the turtle utricle to detect wide dynamic range.

An operating principle of the turtle utricle to detect wide dynamic range.
Hear Res. 2017 Oct 09;:
Authors: Nam JH
Abstract
The utricle encodes both static information such as head orientation, and dynamic information such as vibrations. It is not well understood how the utricle can encode both static and dynamic information for a wide dynamic range (from <0.05 to >2 times the gravitational acceleration; from DC to > 1000 Hz vibrations). Using computational models of the hair cells in the turtle utricle, this study presents an explanation on how the turtle utricle encodes stimulations over such a wide dynamic range. Two hair bundles were modeled using the finite element method-one representing the striolar hair cell (Cell S), and the other representing the medial extrastriolar hair cell (Cell E). A mechano-transduction (MET) channel model was incorporated to compute MET current (iMET) due to hair bundle deflection. A macro-mechanical model of the utricle was used to compute otoconial motions from head accelerations (aHead). According to known anatomical data, Cell E has a long kinocilium that is embedded into the stiff otoconial layer. Unlike Cell E, the hair bundle of Cell S falls short of the otoconial layer. Considering such difference in the mechanical connectivity between the hair cell bundle and the otoconial layer, three cases were simulated: Cell E displacement-clamped, Cell S viscously-coupled, and Cell S displac...

Source: Hearing Research - October 9, 2017 Category: Audiology Authors: Nam JH Tags: Hear Res Source Type: research